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In this study, the effects of the ratio of a motor’s axial length to its pole pitch on efficiency, magnetic flux density distribution, torque, torque/weight, and motor volume were investigated in an outer-rotor (hub) brushless direct current motor. The weight and volume of an electrical machine affects the output power, efficiency and output torque, and it is advantageous to design an electric motor at an appropriate power and high efficiency with an appropriate weight and volume. Therefore, the aim of this study was to optimize the motor’s axial length and stator outer diameter, which affects the motor volume. Initially, the axial-length-to-pole-pitch ratio of the hub BLDC motor was taken at 0.75. According to this ratio, the dimensions of the rotor outer diameter, rotor inner diameter, stator outer diameter, stator inner diameter, slot height, motor axial length, and magnet thickness were optimally determined. Then, the axial-length-to-pole-pitch ratio was considered as 1, 1.50, 2, and 3, respectively. The effects of the change in the motor’s axial-length-to-pole-pitch ratio on the efficiency, torque, speed, torque/volume, torque/weight, and cogging torque were examined in a simulation environment. According to the motor’s axial-length-to-pole-pitch ratio, the torque value in the final state was 28.65% higher than the torque value in the initial state. In the last part, the motor axial length and the stator outer diameter were defined as variables in a genetic algorithm procedure and optimized. The number of poles and the number of slots were fixed parameters. Simulation studies were carried out using the finite element method via AN-SYS/Maxwell software.

The Malampaya field development comprises subsea wells in 820 meters water-depth producing via a subsea manifold and two 16 inch diameter inconel clad flowlines to a shallow water platform 30 km distant. Condensate is removed on the platform and the dry gas is then transported via a 504 km long 24 inch export pipeline to an onshore gas plant at Tabangao (Batangas, Luzon Island) for extraction of H2S. The condensate is stored in the platform CGS Caisson prior to export via a short 3 km long 24 inch diameter pipeline and CALM buoy (Fig 11). The Malampaya Deep Water Gas to Power Project in the Philippines has delivered first gas as advertised on October 1st 2001. The gas production is from five high rate deep water subsea gas wells. This paper summarises the delivery of the wells, in particular, the specific challenges that had to be surmounted to deliver high quality wells whilst remaining within the tight Malampaya project schedule. These challenges related to the deployment of leading edge well technology systems in an environmentally pristine and remote area. This within a country with extremely limited petroleum infrastructure and very long supply lines. The definition and management of good performance within this context and the management of the many interfaces with other disciplines working concurrently required unique ways of working to be established. Within the technical arena, many novel solutions were adopted with respect to rig modifications, drilling with losses, management of hydrates, horizontal Xmas trees, monobore well completions, coiled tubing perforating from a semi-sub well test clean-up and extensive/detailed planning. Organisationally, a working atmosphere was developed based on open, detailed and relentless inter-team challenge. This led to drilling and completing, genuinely to the "limit" of what was achievable for Malampaya. INTRODUCTION Malampaya, developed and operated by Shell Philippines Exploration BV (SPEX), is the first and only gas development in the Philippines. The five subsea wells are the first link in a production chain that supplies 30% of the mainland power requirements. In each well, high deliverability and high availability are critical from day one and throughout the full 25 year field life. There are no other fields that can supplement any shortfall in well performance. Planning was initiated in Houston in late 1998 and moved to Singapore and Manila in mid-1999. Offshore execution started in early-2000 and was completed by September 2001. Innovative business processes and technical solutions were employed in "striving for excellence" in an environment characterised by a very short planning time and a multitude of project interfaces. The Malampaya gas wells were handed over to the production team, on time and within budget. They have been proven capable of production rates exceeding 120MMscf/day. Included in this paper are the key highlights from planning, drilling, completing and commissioning the Malampaya gas wells.

The use of brushless DC (BLDC) motors in electric vehicles have been rapidly increasing. In this study performance analysis was made for BLDC motors used in wheel applications in light electrical vehicles on issues such as efficiency, speed, and power density. In this study, two types of BLDC motors, axial flux (AF) and hub (outer rotor-radial flux) motor were simulated, optimized, and experimented. Both of them were studied considering multi-parameter objectives mainly, stator yoke flux density, rotor yoke flux density, air gap flux density, efficiency, torque/weight, and speed. The credibility of the models performed has been confirmed by comparing the results of simulation and measurement on rated values 10 kW, 72 V (Axial) and 1 kW, 50 V (Hub) 3 phase, star connected motors. To optimize the motor design comprehensively, a genetic algorithm (GA) has been realized for each motor. The design, optimization, and realization of the study are given in detail pointing out some important data on BLDC motors.

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